Composition and zoogeography of marine-estuarine fish from a lagoon system in a temperate-tropical transition zone of the Eastern Pacific

Abstract

We present an updated systematic checklist of fishes from the Bahía Magdalena-Almejas lagoon system (Mexico), including notes on taxonomy, zoogeography, and conservation status, supported by field samplings and the critical review of published and online data. The ichthyofauna is composed by 2 classes, 30 orders, 104 families, 240 genera and 416 species, mainly represented by the class Actinopterygii. Zoogeographically, the fishes showed highest affinity to the San Diego (87.2%), Cortez (81.4%) and Mexican (70%) provinces, reflecting the ancient relationship between the Californian and Tropical Eastern Pacific regions and the existence of a transitional zone in the Baja California Peninsula for fish assemblages from boreal-temperate and warm-tropical derivation, standing out the presence of the endemic Paraclinus magdalenae. The 91% of the ichthyofauna is included by the IUCN Red List as Lower Concern, Data Deficient and Not Evaluated, while Holacanthus clarionensis and Hippocampus ingens, are under Special Protection by the Mexican regulation. Ecologically, 233 species are marine-euryhaline and 177 marine-stenohaline, which preferentially inhabit soft (57%) and rocky (27.5%) bottoms; most species are demersal (60%), benthic (25%) and pelagic (14.4%). The updated checklist could improve the design and implementation of effective fishing regulation strategies and conservation programs for fishes inhabiting this coastal ecosystem.